Mortality rates for colon cancer are four to five times higher in the United States compared to Mexico. The rate of colon cancer in Mexican- Americans living in the United States is beginning to reflect the U.S.pattern. Physical activity has been linked with risk for colon cancer. Large scale epidemiological research into the relationship between activity and cancer in Hispanics cannot easily be conducted until a simple culturally sensitive tool has been designed. It is the purpose of this research project to develop such a tool. The instrument will be designed and tested with adult Mexican-Americans living in Tucson and adult Mexicans living in a northern Sonora, Mexico community. The following methods will be used to design and test the activity questionnaire. First, using anthropological methods of observation, interviews, and focus groups, design a culturally-sensitive physical activity questionnaire (PAQ). Second, test the reliability or reproducibility of the PAQ by administering the questionnaire to the same respondents three times at one month intervals and compare the results. Third, validate the PAQ for estimation of average daily energy expenditure by comparing PAQ results to energy expenditure estimates calculated using the heartrate method.